hi,

Openerp provide 2 modules to avoid negative stock issue.you can download the modules in the following links:

1. Prohibit negative stock quantities

https://apps.openerp.com/apps/modules/7.0/c2c_stock_negative/

2. Sale Exeptions ---https://apps.openerp.com/apps/modules/7.0/sale_exceptions/,

these two modules will help for you to avoid negative stocks

hi,

I had installed the "Sale Exceptions" module, and added the following Rule:

if line.product_id.qty_available < line.product_uom_qty: failed=True

This validation only affects the Sales Order creation; but from the eCommerce side, the Quotation is still created without restrictions.

Regards